The problem of disposing excess, aging, unstable munitions stockpiled around the world has been handled in various ways ranging from simply ignoring them, openly burning/openly detonating (OB/OD) them, land burial, open sea disposal, and the limited conversion or sale of excess explosives for use by the mining industry. Most of these past practices are now unacceptable because of stringent environmental regulations. Specifically, burning/detonation produces airborne particulate and pollutants and releases toxic compounds. Burial that is not sealed also releases toxic compounds into soil and groundwater. Additionally, the conversion of military explosives into mining-grade explosives is expensive and only removes a small percentage of a nation's stockpile from the inventory. That is why Andrews et al. method using hydrogen peroxide requires 24 hours to degrade 100 ppm explosive and is very inefficient because of the need to generate sufficient OH to replace that which is lost prior to reaction. Even though TNT is more soluble than, say HMX and RDX (less than 2 ppm), the limited availability of generated hydroxyl radical because of its instability, Andrews et al. method is highly inefficient, extremely slow, and expensive in terms of capital equipment needs and labor.
U.S. Pat. No. 5,370,845 (Miller et al.) uses an organic solvent up to 30 wt % thereby overcoming in part the concentration limitation of U.S. Pat. No. 4,038,116, but still relies upon ultraviolet light exposure for a time from 5 to 30 minutes. This light exposure is achieved with a bank of ultraviolet lamps and a shallow stream. A free-radiacal initiator may be added to enhance the photolytic degradation. Free-radical initiators are organic peroxide, persulfate, hydrogen peroxide or ketones.
Recognizing the limitations of photolytic degradation, efforts were made to develop non-photolytic degradation of explosives as illustrated, for example in U.S. Pat. No. 5,763,736 (Daume) wherein explosive material is combined with a reaction medium that is aqueous containing a polar aliphatic non-saponifiable solvent. When a strong base is included, it is NaOH or KOH. Reaction time is 0.9 hour. A disadvantage of this method is that it is highly exothermic causing boiling of the reaction medium as the explosives are added thereto.
Hence, there is a need for a method of disposing of explosives (nitro-compounds) that has both the advantages of the photolytic and non-photolytic degradation methods without their attendant disadvantages.